This high-energy portion of the
EM-band is only
visible from space. Between 1949 to 1962, sounding
rockets traveling up to 100 km above the surface
would carry Geiger counters to measure X-ray
emission. A sounding rocket is nothing more than a
standard rocket with the Geiger counter and other
related electronics housed in within the nose.

By 1970, several orbiting X-ray observatories
would begin capturing valuable data. These include
the following observatories:

The ultraviolet (UV) region of the
EM-band allows
the study of very hot, young
stars. Additionally,
populations of young, hot
stars within the disks of
spiral
galaxies are within easy view of a UV
telescope. This also requires satellite
observatories. Here is a list of UV observatories:

Gamma rays are the highest energy radiation
resulting in extremely short wavelengths. Sources of
gamma rays are
supernovas, neutron
stars, intense
gravity regions and active
galaxies (galaxies with a
large and active black hole at the center). Here is
a list of some gamma ray satellites: